Question: The $24^\text{th}$ day of a particular month is a Saturday. On what day of the week was the first day of that month?
Answer: If the $24$th is a Saturday, the $17$th was also a Saturday, as were the $10$th and the $3$rd.  So the $2$nd was a Friday and the $1$st was a $\boxed{\text{Thursday}}$.